1080ti SLI setup with 4x 34" curved moniors

[Kicksome]

Hi Everyone,
Do you guys think it's worthwhile having 2x 1080ti in SLI mode with:
3x Acer CZ340CK 34" Curved UltraWide QHD IPS - (3440 x 1440)
and
1x LG 34" 3440 x 1440 (the one above the middle monitor)

Or should I not SLI them and just connect 2 to one card and 2 to the other? If I'm running multiple instances in different monitors that seems like it might be better performance? Or just don't even use 2 cards? I already have 2x cards, but could put one in another computer.

This is on a i7-5960x @ 4.4ghz 8/16 core, 64 gigs memory, 1TB NVMe 960 Evo M.2.

Here's a picture of the setup for reference:

[MiRai]

Kicksome is always showing off.

Hi Everyone,
Do you guys think it's worthwhile having 2x 1080ti in SLI mode with:
3x Acer CZ340CK 34" Curved UltraWide QHD IPS - (3440 x 1440)
and
1x LG 34" 3440 x 1440 (the one above the middle monitor)

Or should I not SLI them and just connect 2 to one card and 2 to the other? If I'm running multiple instances in different monitors that seems like it might be better performance? Or just don't even use 2 cards?

It really all comes down to doing your own testing while monitoring your hardware. If you want the full available power of each GPU, then you'd want to split them up between the monitors, but that also comes with drawbacks.

[mbox_bob]

Ya, test it out, see if you need two 1080Ti's to run them pixels.

Also, large number of bricks on the desk. I dislike monitors with more bricks.

[Bollwerk]

I could have sworn ISBoxer didn't work well with SLI. Did that change at some point?

[MiRai]

I could have sworn ISBoxer didn't work well with SLI. Did that change at some point?

SLI compatibility is dependent on the game you're playing; IS/ISBoxer has nothing to do with it.

[Vecter]

My own experience with SLI leaves a lot to desire, just such a finicky technology. I would be most incline to just split the cards amongst the 4 monitors, but as MiRai stated testing really is the only way to see what issues you may have with or without SLI.

Nice setup btw, I am liking those curved monitors. I may have to head that direction and just place my 4k monitor above them

[Kicksome]

...
If you want the full available power of each GPU, then you'd want to split them up between the monitors, but that also comes with drawbacks.

What sort of drawbacks? I'm just curious if there are other drawbacks besides you won't get better than single card performance on one monitor? Or is there some sort of CPU/Memory/Windows issues when it has to switch between two video cards. I could imagine spanning a single instance of a game on multiple monitors that are on two video cards (non-sli'd) would incur some sort of penalty, but I didn't plan on that.

[MiRai]

What sort of drawbacks? I'm just curious if there are other drawbacks besides you won't get better than single card performance on one monitor? Or is there some sort of CPU/Memory/Windows issues when it has to switch between two video cards. I could imagine spanning a single instance of a game on multiple monitors that are on two video cards (non-sli'd) would incur some sort of penalty, but I didn't plan on that.

You would need to build a Window Layout around the fact that you shouldn't be swapping game clients between monitors because they'll incur a penalty in performance.

If a game client starts up on a particular monitor, then the GPU attached to that monitor is the one that is rendering that specific game client. If that game client moves to another monitor (e.g. if your window layout uses cross-monitor swapping), then the GPU that it started off attached to is no longer going to be able to render it on another screen which is attached to a different GPU, and therefore it is now being rendered through software rather than hardware, which is where a drop in performance is likely to be seen.

On the other hand, when using SLI you don't get 200% of two GPUs, or 300% of three GPUs, and there are normally diminishing returns when using a multi-GPU setup to render, but you can still use a multi-monitor layout and swap between monitors.

The choice is yours.

[daviddoran]

I'm debating adding a second GTX 1080, or upgrading to a 1080 Ti. I'm running all my wow windows in a single 4k monitor, so it would seem that SLI might be the way to go. I have to keep the quality down to get the frames up, so I definitely need to upgrade somewhere. Probably be easier to find a second 1080, the Ti are gonna be out of stock for a while.

[Kayley]

I run a similar setup only mine is Watercooled and stupidly overclocked.. vroom vroom.

In WoW (only game I really mbox) when I played 15+ characters without SLI and running each card independently on a monitor (I only run 1440p, x3 monitors) I would experience a lot of weird slowdowns and what I called 'hiccups' where it would freeze for half a second then catch up. Using that nifty HWinfo program it showed the GPUs (980ti's x3) randomly hitting their limit (core load, memory usage) which caused the stuttering.

Turned on SLI and everything smoothed out and i'm hitting my cap of 60fps with no issues. Saw no benefit of 144fps in a game like WoW haha.. it's not that competitive..
ANYWHO. I'm in Dalaran right now, 15 characters spamming spells.. the area is packed and my GPUs in SLI are showing a 38% memory usage and a core/bus load of under 14%. Which is sweet FA. My advice is to buy ALL THE VIDEO CARDS!